Genetic diversity of 33 forage cactus pear accessions based on principal component analysis


  • Saleem K. Nadaf
  • Safa'a M. Al-Farsi
  • Saleh A. Al-Hinai
  • Aliya S. Al-Hinai
  • Abdul Aziz S. Al-Harthy
  • Saif A. Al-Khamisi
  • Ahmed N. Al-Bakri


Cactus pear, cladodes, fodder yield, principal component analysis


The present research was undertaken to assess genetic diversity of 33 forage cactus pear
accessions introduced from different countries for their suitability in the existing fodder
production system in Arabian Peninsula countries including Oman. These accessions were
evaluated in randomized complete block design with four replications for two consecutive years
2014 and 2015 at Agriculture Research Center, Rumais in Oman. The characters cladode
green and dry matter yields and their related traits plant height (cm), number of cladodes and
cladode weight were considered for study. The results of principal component analysis (PCA)
indicated that of the total four components, the first two components PC1 and PC2 accounted
for 97.65 and 2.27%, respectively which in combination contributed to 99.92% of the total
variation among characters studied in fodder cactus pear accessions whereas remaining two
components PC3 (0.06%) and PC4 (0.02 %) contributed a meagre 0.08% to the total variation.
The first principal component had high positive loading for only green matter yield with the
highest value of 0.993 whereas second principal component had highest loading for plant
height (0.998) in contributing to the diversity. However, PC3 and PC4 were accounted by higher
positive loading in respect of dry matter yield (0.853) and number of cladodes (0.855). The
results of correlation analysis indicated that of 10 possible correlations from five characters
studied, seven correlations which were found significant (p<0.05) were also positive in nature
of association. The scatter of accessions based on PC1 and PC2 scores resulted in grouping
them into six clusters consisting of accession ranging from 1 to 9. These results could be
applied in either selecting higher green matter yielding accessions from high yielding groups to
recommend for either general cultivation or planning and execution of future breeding program
for higher forage productivity in cactus by selecting accessions from different clusters as
parents for hybridization.






Scientific Papers